<template>
  <div id="app">
    <router-view/>
  </div>
</template>

<script>
export default {
  name: 'App',
  created () {
      //在页面加载时读取sessionStorage里的状态信息
      if (sessionStorage.getItem("store") ) {
          this.$store.replaceState(Object.assign({}, this.$store.state,JSON.parse(sessionStorage.getItem("store"))))
      } 
  
      //在页面刷新时将vuex里的信息保存到sessionStorage里
      window.addEventListener("beforeunload",()=>{
          sessionStorage.setItem("store",JSON.stringify(this.$store.state))
      })
    }
}
</script>

<style>
#app {
  font-family: 'Avenir', Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-align: center;
  color: #2c3e50;
}
body{
  margin:0;
  padding:0;
}
</style>
